
About dust extraction systems
Main functions of dust extraction system:
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better working conditions and protection of workers,
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protection of the environment and machines,
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energy savings,
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recycling of waste material.
Picture 1: Elements of a single system
Picture 2. Installed dust extraction system – PELET GRUPA, Novska
Depending on the type and amount of suction and filtered dust, there are types of filtering devices. The main division is positive pressure and negative pressure systems.
In the case of non-abrasive dust, a pressure system (pressure filter) is used. The material passes through the fan and in the filter the bulk of the dust is separated gravitationally and the smaller part on the filter surface. Due to the low load, such filters, if well selected, work without additional shaking. If the specific filter loads are large, which is typical of abrasive dust in the wood industry, and almost always in cement, food, chemical and other industries, pressure filters are supplemented with bag shaking (regeneration) systems. There are three ways to shake a filter bag, which are:
Picture 3. Example of negative pressure system –DALSTROJ ADRIA WINCH, Split
Picture 4. Example of positive pressure system –VEKTRA JAKIĆ, Pljevlja
Separated dust in the filter should be removed from the filter as soon as possible to prevent it from clogging or accumulating a large amount of entrained dust, which in some conditions presents a high risk of fire and explosion.
For lightly loaded filters, as well as for filters in industries where the footprint is very dusty, it is sometimes sufficient to use PE bags or a pressurized bin (metal container) as a container. For larger units, the discharge of the material is solved by a chain or auger transport via a rotary air inlet (dispenser) which seals the filter with pressure, and gravity discharges the material gravitationally from the filter.
Depending on the further use of the filtered material and the automation of the plant, the material is transported to a silo or container or directly fed to the boiler room or briquette.